const citys = [
  {
    provinceName: '北京市',
    mallCityList: [
      {
        cityName: '北京市',
        mallAreaList: [{ areaName: '东城区' }, { areaName: '西城区' }]
      }
    ]
  },
  {
    provinceName: '辽宁省',
    mallCityList: [
      {
        cityName: '沈阳市',
        mallAreaList: [{ areaName: '和平区' }, { areaName: '沈河区' }]
      }
    ]
  }
];
module.exports = citys;   // 关键：直接导出数组